Abdul Hadi Arwani, a Syrian preacher at An-Noor Mosque in Acton, was found with a gunshot wound to his chest.YouTube

Counter-terrorism police are investigating the murder of Imam Abdul Hadi Arwani, it has emerged. News that specialist officers have taken over the probe comes amid reports of a video in which Arwani claimed to have been "sentenced to death" by the Syrian government.

A Scotland Yard source said counter-terrorism officers were looking in to a possible foreign dimension of the crime, utilising a network of contacts overseas. Unconfirmed claims have been made that Arwani was the target of a "state-sponsored assassin" who shot him dead in a car in Wembley, north London.

Arwani reportedly alleged he was living under a death sentence in 2012, during "Syria crisis week." He said he was condemned for photography a massacre site in 1982. But this theory has been rejected by relatives of the 48 year-old father of six and also Middle-East experts.

Arwani's daughter Elham, 23, said: "We have no idea what happened. We don't even know how he was killed. We have just been told he was killed and that's it. Any Syrian who is free and who knows the truth is against Assad. It's not going to be because he was against Assad. It must be for another reason, but we can't think of anything."